Oh come on! It was obviously MVP.
1..2 you hear the clock ticking.
*Vince knows the end is coming soon and his time is limited, he let us know this several times*
Tick Tock You're about to stop living (Tick-tock is also a reference to the bomb).
*MVP warning Vince that his end is near*
Tick Tock I want you to remember me
But the dead don't have a memory
*MVP taunts Vince*
I'm coming!
Nobody can stop, Ain't nobody can hold me, Ain't nobody control me.
*MVP, a renown Muslim and follower of Malcolm X, refuses to leave his career in the hands of "The Man", in this case Vince McMahon. He makes it clear that no one (Vince) will stop his rise to fame, no one will hold him down (Vince) and nobody will control his character (Vince).
And guess who was in jail for 9 and a half years? That's right, Montel Vontavious Porter, MVP!
Edit: I still say its MVP, but this video says otherwise.
http://www.dailymotion.com/tag/wwe/video/x28q9k_the-killer-of-vince-is-found